what is the function of rectus femoris muscle?

adjacent anatomical anatomy ankle anterior aponeurosis bipenniform body brevis compartment deep dermis digitorum downward eversion extend femoris fibers fibularis flexion foot fusiform human intercostal internal lateral leg longus midline muscle muscles muscular musculoaponeurotic oral orbicularis organ oris peroneus plantar rectus resctus run shape sole sphincter straight superficial tibialis toes wingshaped